This invention relates to a multi-filament dental floss where at least a portion of the floss is comprised of polytetrafluoroethylene filaments. More particularly this invention relates to a dental floss where polytetrafluoroethylene filaments comprise from about 10 percent to about 90 percent of the filaments of the dental floss.
Dental flosses come in two different forms. These forms are as multi-filaments and as tapes. As a tape the floss will have a denier of about 1200 to 3000 or more. As multi-filaments the individual filaments have a denier of about 100 to 800. The advantage of a multi-filament over a tape is that in use the filaments of a multi-filament floss splay and assist in the removal of food particles, debris and plaque from between the teeth and under the gum line. This enhanced cleaning comes from the splayed filaments each rubbing the surface of a tooth. The use of a plurality of filaments appears to exhibit an increased removal of certain particles and plaque.
In the present instance the objective is to combine the advantages of polytetrafluoroethylene filaments with those of other filaments. Polytetrafluoroethylene has the advantage of a low coefficient of friction of about 0.08 and lower. Since it has a low coefficient of friction it readily passes through the narrow spaces between teeth. In fact, it is too lubricous and is difficult to grip. This problem of polytetrafluoroethylene being too lubricous can be modified by using the polytetrafluoroethylene filaments in combination with other filaments. These other filaments all have coefficients of friction that are greater than polytetrafluoroethylene. Upon the combination of such filaments with polytetrafluoroethylene the coefficient of friction is increased. The floss has a coefficient of friction that permits it to easily pass between adjacent teeth but yet to be readily gripped. The polytetrafluoroethylene filaments provide lubricity and the non-polytetrafluoroethylene filaments provide for a gripping of the floss.
The state of the art of present commercial dental flosses is exemplified by (U.S. Pat. No. 4,414,990, U.S. Pat. No. 4,033,365 and U.S. Pat. No. 3,943,949 which disclose the use of various non-polytetrafluoroethylene filaments as a floss. U.S. Pat. No. 5,033,488 discloses a different floss the use of a single strand of expanded polytetrafluoroethylene that has been coated with a microcrystalline wax as a floss. The microcrystalline wax increases the coefficient of friction so that the strand of polytetrafluoroethylene can be more easily gripped. The problem of a difficulty in gripping was solved by adding a wax coating. However, this now can also be resolved through the use of a mixture of fibers. The various non-polytetrafluoroethylene fibers that have been used consist of a selection of natural and manufactured filaments. A wax coating is used on nylon and related filaments as a lubricating agent. The most used filament material is nylon. The flosses can be wax coated or have no coating. In addition, the flosses can be coated with a flavorant, fluoride or other substance. The expanded polytetrafluoroethylene that is used is a particular polytetrafluoroethylene.